Cloverly, Morrison, and Sundance Formations

Cloverly Formation - Rusty sandstone at top, underlain by brightly variegated bentonitic claystone; chert-pebble conglomerate locally at base. Morrison Formation - Dully variegated claystone, nodular limestone, and gray silty sandstone. In southern Yellowstone and Jackson Hole areas the presence of Morrison is questionable. Sundance Formation (Js) - Greenish-gray glauconitic sandstone and shale, underlain by red and gray nonglauconitic sandstone and shale.
State Wyoming
Name Cloverly, Morrison, and Sundance Formations
Geologic age Middle Jurassic-Lower Cretaceous
Lithologic constituents
Sedimentary > Carbonate > Limestone
Sedimentary > Clastic > Mudstone > Claystone
Sedimentary > Clastic > Sandstone
Sedimentary > Clastic > Mudstone > Shale
Sedimentary > Clastic > Conglomerate
Sedimentary > Chemical > Chert
Sedimentary > Clastic > Mudstone > Claystone > Bentonite
NGMDB product
Counties Albany - Carbon - Converse - Fremont - Johnson - Laramie - Natrona - Park - Platte - Washakie